This invention is directed toward an improved felling head for use in harvesting trees.
The invention is more particularly directed toward an improved felling head employing two adjacent circular saws to cut a tree to be harvested.
Felling heads with tree cutting means are well known. Many felling heads employ shears to cut through a tree. The use of shears however often results in splinter damage to the cut tree at its butt end and leads to high wastage. It is also known to employ felling heads having chainsaws to cut trees. The chainsaws minimize the problem of damaging the butt end of the cut tree but they are expensive to operate and service and binding problems are often encountered in using chainsaws.
It is also known to employ harvesting machines with a single, large circular saw to cut through the tree to be harvested. Examples of such machines are shown in Canadian Pat. No. 898,661 or Canadian Pat. No. 1,029,283. In such machines however, the saw must be both quite large in diameter and quite thick. As a result, the saw is very heavy and requires a relatively large amount of power to operate it. The thick circular saws waste wood in cutting through a tree. The large, heavy circular saws are also difficult to service and/or replace. The teeth on the saw often break when the saw strikes ground or a rock. Because of the size of the saw, replacement costs are high. The known circular saws are fixed in one position on the harvesting machine. Thus the rate of tree harvesting is limited by the manoeuverability of the harvesting machine. Special steps must also often be taken to avoid binding during operation of the saw which increases the cost of such saws.